Associate Health Minister Jo Goodhew says she can't give an assurance District Health Boards won't have to take over managing more resthomes, but changing the audit system would not improve care.
New Zealand First wants to see changes to the auditing process after the Canterbury DHB took control of two resthomes following complaints during their certification process.
The party says it has received many allegations about substandard care at several resthomes and the auditing process must be improved.
Wiltshire Lifecare in Rangiora and Bermuda House in Upper Riccarton are now under the control of the DHB after complaints about their standard of care.
In Wiltshire's case, audits dating back to 2009 followed complaints about staffing, nutrition, heating and poor palliative care.
New Zealand Aged Care Association chief executive Martin Taylor says the audit system is already robust, with more than 600 audits done a year on just 694 resthomes.
Mr Taylor told Radio New Zealand's Nine to Noon programme on Friday that in Wiltshire's case, a poor management decision was made, but was not checked.
"They have a long history of providing good care and, yes they've dropped the ball. But we found out that they have and we're working with them to ensure that they can get up to that standard again."
Mr Taylor says to have DHBs take over is preferred to closing facilities and leaving residents without a bed.
The associate minister told Nine to Noon she implores people worried about the level of care to discuss issues with resthome managers, the local DHB, the Ministry of Health or the Health and Disability Commissioner.
"In any care environment where there are human beings working, sometimes somebody will not be doing the highest quality job that they should be - but we need to be able to identify that and respond to it."
Ms Goodhew says the health system is responsive to addressing issues and a programme to improve training is being rolled out.